The present invention relates to passively damped, vibration and shock load isolation apparatus suitable for use in protecting hardware and payloads from damaging vibration and shock loads, particularly those extreme loads seen in spacecraft launch systems. This application incorporates by reference all that disclosed within U.S. Pat. No. 6,202,961.
The ability to isolate payloads from the vibration and shock loading of a supporting structure or vehicle, or conversely to isolate a structure or vehicle from the vibrations of an engine, motor, or other vibration inducing payload is of great value to the aerospace, automobile and vehicle industries world wide. The particular ability to provide substantial passive damping and vibration isolation in a compact and lightweight form, together with a completely linear elastic, high-strength load path has been the strength of the device disclosed in U.S. Pat. No. 6,202,961.
A further characteristic of performance that is desired within vibration isolation devices is the ability to provide an independent and widely controllable compliance in all directions of vibration loading without sacrifice to strength and linearity of behavior, and without sacrifice to compactness or weight.
High strength and linear load-deflection performance in all directions is highly desirable to mandatory in most vibration isolation applications. For spacecraft—launch vehicle applications, large magnitude vehicle accelerations having both longitudinal and lateral directional components require that high strength be maintained in all directions. Further, the overall system dynamics of the spacecraft and launch vehicle system must be predictable and carefully controlled, thereby the demand to avoid non-linear elastomers within the load path is without compromise. Additionally, extreme loads environments drive up the size and strength requirements of the payload and payload-to-launch vehicle interface hardware, such that the mass and space requirements of the apparatus must be continuously and aggressively minimized, thereby minimizing the cascading design impact to supporting hardware.
A three-axis vibration isolation device patented earlier in part by this pair of inventors, disclosed in U.S. Pat. No. 6,290,183, provided the independently controllable, high strength, linearly elastic, multiple-axis compliance that is desired but with some sacrifice to longitudinal compactness. Damping within that device was also limited to the constrained-layer-on-beam-bending damping approach of the time, and effective primarily for longitudinal motions. Damping in the lateral directions of that device was light and thereby required any significant lateral motion damping to be added through means separate from the device.
The device of U.S. Pat. No. 6,199,801, disclosed by the present two inventors and upon which the device of U.S. Pat. No. 6,290,183 was an extension, was the first its kind to provide for a passively damped vibration isolation device with high strength and linear-elastic performance. Other earlier approaches for vibration isolation and damping implementation wherein elastomers are used in the primary load path, remain inferior to those which maintain use of high-strength, linearly elastic materials throughout the primary load path. The device of U.S. Pat. No. 6,199,801 remained relatively stiff against lateral loading as compared to its longitudinal loading and thereby did not afford the desired levels of laterally directed vibration isolation. Hence the device of U.S. Pat. No. 6,290,183 answered the need for improved lateral vibration compliance but had its own limitations in terms of higher profile and light damping.
The present invention addresses the need for a passive, highly damped vibration isolation device which provides independent and widely controllable compliance in all directions of vibration loading without sacrifice to strength and linearity of behavior, and without sacrifice to compactness or weight.